1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method. More particularly, the present invention relates to an image processing apparatus and an image processing method suited for portable apparatuses, such as digital cameras and digital video cameras.
2. Description of the Related Art
In imaging apparatuses, such as digital cameras and digital video cameras, raw data (RGB data) obtained by A/D converting output signals of an imaging device is initially stored in a memory. Then, the raw data stored in the memory is converted into YC data by an image processing circuit. The image processing circuit is provided with a temporary storage circuit for writing the raw data read from the memory and an arithmetic circuit for executing arithmetic processing using the raw data of plural pixels read from the temporary storage circuit. FIG. 38 shows an example of a sequence wherein the raw data read from the memory is written to the temporary storage circuit for conversion processing. Specifically, the raw data is read sequentially for every horizontal pixel row (line) in one image 300. The conversion process requires plural adjacent pixels in the horizontal direction and/or vertical direction. Therefore, the writing sequence shown in FIG. 38 requires a large-capacity line memory capable of storing the pixels included in one line of the image 300 as a temporary storage circuit, thereby the image processing circuit becomes large in size.
Japanese Laid-open Patent Application No. 2000-354193 discloses that the image 300 is divided into plural blocks (image blocks 301) as shown in FIG. 39 and that the raw data in every image block 301 is read from the memory and processed. When the reading method shown in FIG. 39 is adopted, the line memory should only have a storage capacity capable of storing the pixels included in one line of the image block 301. This reduction in the storage capacity of the line memory can reduce the size of the image processing circuit.